Ballistic missiles carrying nuclear weapons and the proliferation of nuclear weapons represent two of the gravest threats to the security of the United States, its service members, and allies. It may come as no surprise that the international threat environment the U.S. will face for many decades to come will be fundamentally different from the Cold War era and different from today's global fight against terrorist organizations and extremism. The list of global actors who possess ballistic missiles or seek to acquire the technology has grown exponentially over the years from a total of nine countries in 1972 to 33 countries today. Rogue states, chief among them North Korea and Iran, continue to place a premium on the acquisition of nuclear weapons technology and the platforms to delivery them. Both India and Pakistan have active nuclear programs and North Korea solidified its position in the world as a nuclear-capable state. While Russia contains that world's second largest nuclear stockpile, China possesses the world's most active ballistic missile development program.